They are. Yup. This is one of the hurdles they have to jump, and would've had to jump when it was the Mystic. I'm not saying it's insurmountable. Just that it's a problem.
As far as the Weave, that was more about how they've made ALL MAGIC (including Psionic 'Magic') dependent on the presence of the Weave of Mystra. Which doesn't really work for Dark Sun, where arcane magic defiles the world and siphons life out of it to power spellcraft, but psionics explicitly doesn't because that power is from within yourself.
It's a huge part of the narrative conceit of the setting.
... I mean you could certainly make that setting and slap that name on it. But it wouldn't be Dark Sun.
I'd REALLY love that... I just see it as another obstacle they have to overcome.
It can be modified, removed, or kept... but it is still a stumbling block. Something for people to debate in the writer's room. Some on one side thinking it's indefensible, others thinking it could be kept as is, and others trying to argue a middle ground of changing it.
None of these obstacles are insurmountable. They're just a variety of points that combine to make a bigger overall problem, is my argument.
In favor in pop culture... but are they in favor with the D&D community, -specifically-? Marvel characters are in favor in pop culture to the tune of billions of dollars of licensing rights for Spider-Man. That doesn't mean the average 5e players who has only really engaged with various high fantasy settings wants WotC to release a Marvel Superheroes setting where Wolverine is the Iconic Barbarian and they're eager to buy the book the day it drops.
Will it be popular with their current consumer base in the context of the game itself is still a big question, even if other social indicators hint at a relative popularity in the cultural zeitgeist.
They kinda do... but also they really don't.
If whatever's popular outside of D&D were brought into D&D because it was popular we'd have a very different selection of campaign settings and books released. Instead, we see WotC cleaving close to high fantasy in everything.
Lemme demonstrate it differently. Here's the top 15 books according to AlphaStream's article from September 2023 found here:
How D&D Sells and What It Means for the Hobby
This is based on the Bookscan data revealed here:
As you can see, Curse of Strahd and Eberron: Rising from the Last War are the two campaign settings on the top 15 list and sold, between the two of them, about 290,000 copies. Out of the 1.5 million people who owned a PHB by 2023.
Wildemount is down in the 110k range. Ravnica is at the 100k range with Van Richten's Guide to Ravenloft. I watched them scroll down to the 40k range and didn't see Theros.
Granted: This is only the numbers for big box stores and not direct sales or digital downloads, so there's definitely more sales of EVERYTHING on this list.
Settings don't sell that well. Just as a general rule. Because the target audience of a setting is a DM. And DMs make up a much smaller portion of the market.
Then you have the barrier that a lot of DMs make up their own settings. Some might buy other settings for examples or to steal stuff, but that still shrinks your potential market even further.
THEN you get into the popularity of Post Apocalyptic stuff compared to high fantasy. And as we can see, above, high fantasy (Sword Coast Adventurer's Guide, Tasha's, Xanathar's) blows Gothic Horror Fantasy and Magepunk fantasy out of the water. So unless there's a secret trigger word on Post Apocalyptic Fantasy which activates most DMs in a Winter Soldier style purchasing frenzy, that market is going to be significantly smaller than the Forgotten Realms audience.
Are they going to release a Dark Sun setting book? Definitely possible. I think we'll probably see it with a bunch of character options tied to it, rather than a single standalone setting book to try and get a wider audience of players to grab a copy so they can access the Psion class or whatever else is in the book.
But it's a hurdle that they'll need to clear. Another complication in a list of complications. That's what I'm saying.